Preparation and optical features of samarium(III) complexes introducing bidentate fluorinate and secondary ligands

The syntheses of five luminescent samarium(III) complexes based on 6-Fluoro-4-oxo-4H-1-benzopyran-3-carboxaldehyde (L) and bidentate ancillary ligands were reported. The bidentate ancillary ligands were 1, 10-phenanthroline, 2, 2′-bipyridine, neocuproine, and bathophenanthroline. The complexes were characterized by employing elemental analysis, UV, FTIR, ESI–MS⁺ spectrometry, TGA, FESEM, and PXRD. The luminescence properties of complexes in solution and powder state have been discussed to investigate optical characterization. The complexes display characteristic luminescence peaks of samarium(III) ion at ~ 566, 600, and 647 nm. Different coordination environments around samarium(III) ion in dimethyl sulfoxide solution and powder state result in different emission colors: bright orange and red color with intense peaks at ~ 600 nm and ~ 647 nm. The luminescent quantum yield, decay time, CCT, and CIE coordinates were considered. The replacement of aqua ligands by the bidentate subsidiary ligands from the parent complex enriched emission properties, thermal stability, decay time, and quantum yields. Interesting optical properties of complexes in the orange-red spectral region might be useful in electronic devices, bio-assays, and liquid lasers.